How popular is Nixon?

Nixon is a rare given name for men but a very popular last name for all people (#877 out of 150436, Top 1%). (2000 U.S. Demographics)

Nixon was first listed in 2006 and reached its top position of #512 in the U.S. in 2015. (Top Baby Names, 2015)

Which version is better?

with similar and related boy names. Popular alternative forms of Nixon (#512 in 2015) are Nicholas(#62 in 2015), Nico(#464), Niko(#636), Nick(#1206), Nikko(#1207), Nils, Niels, Nicky, Nicola and Nikki. Adoption of these relations of Nixon was at its highest 2 decades ago (median #1410) and has become much less since (#1280, 73% less usage). Nicholas is more widely used than the rest, although Nico appears to be getting popular too, while versions such as Nick have become less contemporary.